information for all kinds of studio work from all studio areas at the Slade School of Fine Art

Camera aperture

An adjustable camera controls the amount of light reaching the film in two ways. It can make the Image darker or lighter by a variable aperture. positioned behind the lens. and it can control the length of time that the light reaches the film. by a timed shutter. The lens aperture consists of overlapping movable leaves which form a diaphragm.

This can be set to a range of diameters. so that the quantity of light admitted is controlled In the same way that the width of a funnel controls the quantity of water flowing Into a container. When photographing a dimly lit subject you use a wide lens aperture to admit as much light as possible; for a bright subject you can c;hange to a small aperture to reduce the amount of light. In this way the film still receives the same amount of llght.